Presentazione standard di PowerPoint€¦ · Paddon-Row et al. Chem.Eur.J. 1999, 5, 2518 Stang et...
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Self-assembly
Transcript of Presentazione standard di PowerPoint€¦ · Paddon-Row et al. Chem.Eur.J. 1999, 5, 2518 Stang et...
Self-assembly
atom
molecules
covalent
35-135 kcal/mol
high
molecule
assemblies
ionic, hydrophobic, metal-coordination, H-bond
2 - 20 kcal/mol
low (dynamic structures !!!)
Characteristics
building block
target
bond type
bond energy
kinetic stability
Paddon-Row et al. Chem.Eur.J. 1999, 5, 2518
Stang et al. JACS 1999, 121, 2741
+
self-assembly
design principles
information inserted in the building blocks
(coordination, H-bonds, dynamic covalent bonds)
see PDF
COOH
see PDF
What about hydrogen bonding ?
trimesic acid
N
N
N
O
HH
N
N
O
NH
H
HNN
N
O
H
HN
N
ON
H
H
H
N
N
NO
H
H
NN
O
NHH
H
N
N
N O
H
H
H
N N
O
NH H
H
N N
N
O
H
H
HN
N
O N
H
H
H
N
N
N
O
H
H H
N
N
O
NH
H
H
H
H
H
rosette
N
N
N
O
O OH
H H
N
N
N
O
O OH
H H
N
N
N
N
NN
H
H
H
H
H
H
O
HO
N
N
N
O
O OH
H H
N
N
N
N
NN
HH
H
HH
H
O
HO
O
HO
N
N
N
OH
HN
N
N
N
NN
HH
H
HH
HO
H
N
N
NH
N
N
N
N
NN
HH
H
HH
HO
HO
N
N
N
N
NN
HH
H
HH
H
HO
O
HO
N
N
NH
N
N
N
N
NN
HH
H
HH
H
N
N
N
O
O OH
H H
OH
N
N
NH
N
N
N
N
NN
HH
H
HH
HO
HO
N
N
N
O
O OH
H H
N
N
N
N
NN
HH
H
HH
H
HO
O
HO
N
N
NH
N
N
N
N
NN
HH
H
HH
HO
H
N
N
NH
N
N
N
N
NN
HH
H
HH
H
O
HO
N
N
N
OH
HN
N
N
N
NN
HH
H
HH
HO
H
N
N
NH
N
N
N
N
NN
HH
H
HH
HO
HO
HO
N
N
NH
N
N
N
N
NN
HH
H
HH
H
rosette
linear tape crinkled tape
N
N
N
N
N N
H H
H
H H
H
N
N
N
O
O O
H H
H
Isolation of the rosette motif • peripheral crowding
Whitesides
Isolation of the rosette motif • covalent preorganization
Positive cooperativity is due to entropic and enthalpic contributions to binding. Entropy: loss of motion of the molecule, including internal rotation and vibrations (contribution already paid for in connecting together the recognition elements) Enthalpy: secondary functional groups interactions, conformational changes, polarization of the interacting groups
Entropy Enthalpy
What about 3D-hydrogen bonded structures ?
How reliable is the self-assembly process ?
see PDF
DNA Nanofabrication
DNA Nanofabrication
Self-assembly beyond noncovalent interactions
